Sciencemadness Discussion Board

Isolating Mg metal using Pidgeon process for amateurs ?

metalresearcher - 18-9-2024 at 10:28

Buying Mg metal online is way cheaper, but it is just the fun for an amateur chemist.
After a few successful Na and K isolation I realized that distilling such flammable and reative metals is not that difficult, even without using inert gas or vacuum.
This is my theory:
On the largest online chemistry textbook I found that it is done by heating dolomite (Cao.MgO) with ferrosilicon to 1200 C and capturing the Mg. Commercially it is done using vacuum due to a better yield, but even at ambient pressure, Mg boils at 1100 C.
So using a stainless steel tube, one end closed and welded tight and the other end has just a screw cap and an imtimate mixture of the FeSi and MgO is put in the closed end and the other end cosed with the screwed cap. Fore safety one can drill a 2mm hole in the cap, close it and put the other end with the mixture in a 1200 C furnace and keep the screw cap end cool.
After the reaction is finised (no idea how long that lasts: 5 minutes or an hour ??) let it cool and some Mg crtstals should be formed near the screw cap.
A slight upgrade might be an argon cylinder providing a slight flush of the retort.

Any ideas on this ?

Alkoholvergiftung - 18-9-2024 at 11:59

An alternative would be from Karl A. Hoffmann an Chemistry book he wrote an electrolysis of Ammoniummagnesiumsulfate the Double salt under 100C gives magnesium metal. No clear discription of the cell but i think he used an diaphragma.

[Edited on 18-9-2024 by Alkoholvergiftung]

Admagistr - 18-9-2024 at 12:19

Interesting procedure, but it will be technically quite demanding, using vacuum, temperature over 1000 C. And the magnesium obtained won't be very pure. It'll only be magnesium of technical purity. It's on a small scale, more for interest, to try it myself and produce something, which sounds tempting. Are you going to try it?